// Helper mixins

// Useful border shade when dealing with images of unknown color.
@mixin innerBorder($type: 'dark', $borderRadius: 0, $alpha: 0.1) {
  $color: rgba($euiColorDarkestShade, $alpha);

  @if $type == 'light' {
    $color: rgba($euiColorEmptyShade, $alpha);
  }

  position: relative;

  &:after {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: $borderRadius;
    content: '';
    pointer-events: none;
    border: 1px solid $color;
  }
}

// Set scroll bar appearance on Chrome (and firefox).
@mixin euiScrollBar {
  // Firefox's scrollbar coloring cascades, but the sizing does not,
  // so it's being added to this mixin for allowing support wherever custom scrollbars are
  // sass-lint:disable-block no-misspelled-properties
  scrollbar-width: thin;

  // sass-lint:disable-block no-vendor-prefixes
  &::-webkit-scrollbar {
    width: $euiScrollBar;
    height: $euiScrollBar;
  }

  &::-webkit-scrollbar-thumb {
    background-color: transparentize($euiColorDarkShade, 0.5);
    border: $euiScrollBarCorner solid transparent;
    background-clip: content-box;
  }

  &::-webkit-scrollbar-corner,
  &::-webkit-scrollbar-track {
    background-color: transparent;
  }
}

// Just overflow and scrollbars
@mixin euiYScroll {
  @include euiScrollBar;
  height: 100%;
  overflow-y: auto;
}

@mixin euiXScroll {
  @include euiScrollBar;
  overflow-x: auto;
}

// The full overflow with shadow
@mixin euiYScrollWithShadows {
  @include euiYScroll;
  @include euiOverflowShadow('y');
}

@mixin euiXScrollWithShadows {
  @include euiXScroll;
  @include euiOverflowShadow('x');
}

// Hiding elements offscreen to only be read by screen reader
@mixin euiScreenReaderOnly {
  position: absolute;
  left: -10000px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

// Specifically target IE11, but not Edge.
@mixin internetExplorerOnly {
  // sass-lint:disable-block no-vendor-prefixes
  @media screen and (-ms-high-contrast: active),
    screen and (-ms-high-contrast: none) {
    @content;
  }
}
